Robot Description :

STOCH is based on four identical legs that are arranged in an symmetric canine configuration. With linear dimensions of about 0.4 m and a total weight of 3 kg, it has the size of a small to medium-sized dog. Every leg has a total of 2 degrees of freedom, one each for hip flexion/extension, as well as knee flexion/extension. I've put emphasis on keeping the inertia of the moving segments minimal by concentrating all actuators at the main body through the use of parallel four bar mechanism for knee actuation, and simple geared transmission(made with laser cut steel gears) for the hip. The legs are manufactured as the linkages of thin(6 to 12 mm dia.) carbon fiber composite tubes and 3D printed poly lactic acid (PLA) connector parts. To further reduce the weight I've used (experimented) carbon fiber journal bearings at the joints. This weight reduction is beneficial to ensure fast swing leg motion and to reduce impact losses at the intermittent ground contact. The lightweight main body is fabricated as a custom made carbon fiber/epoxy(CF) plates at front and rear which join with CF tubes via 3D printed PLA connector parts . The chassis contains well protected all electronic circuits, sensors and cable routing. Servo motors (Kondo 2350 - 30 kg cm) are used as primary actuator situated at each hip and knee joint. To sense the joint angles the STOCH is equipped with 8 absolute magnetic encoders (Resolution : 1024 CPR) . The body orientation is sensed with an IMU (SparkFun MPU-9250) that includes an accelerometer and gyroscopes. The primary aim of the development of STOCH is to build up the capacity for the lab to experiment with the novel approaches to walking such as reinforcement learning, further it was an extensive exercise which will be helpful to develop another generations of legged robots here at Indian Institute of Science (IISc), Bangalore..

This project is part of work in Robotics at Robert Bosch Center of Cyber Physical Systems at IISc, Bangalore, India.

Recent Work :

• Dhaivat Dholakiya,Shounak Bhattarchya, Ajay G, Abhik Singla, Shalabh Bhatnagar, Bhardwaj Amrutur, Shishir Kolathaya and Ashitava Ghosal,. "Design , Development and Experimental Realization of Quadrupedal Research Platform : Stoch", Accepted to IEEE International Conference of Control, Automation and Robotics (ICCAR), 2019

Pre-print : http://arxiv.org/abs/1901.00697

Video : https://youtu.be/Wxx9pwwTIL4

• Abhik Singla, Shounak Bhattarchya, Dhaivat Dholakiya, Shalabh Bhatnagar, Ashitava Ghosal, Bhardwaj Amrutur and Shishir Kolathaya. "Realizing Learned Quadruped Locomotion Behaviors through Kinematic Motion Primitives", Accepted to IEEE International Conference of Robotics and Automation (ICRA), 2019

Pre-print : https://arxiv.org/abs/1810.03842

Video : https://youtu.be/swcStUm0Nuk